Sigh syndrome and volitional respiratory modulation

Functional breathing disturbances represent a significant clinical overlap among respiratory physiology, autonomic regulation, and interoceptive processing. We report a 35-year-old healthy, athletic male with recurrent episodes of shallow, rapid breaths interrupted by forceful yet incomplete deep inspirations consistent with sigh syndrome. Episodes occurred once or twice a month for 2 years, lasted several hours, resolved with sleep, and produced substantial subjective distress. They were provoked by excess caffeine intake, intense anaerobic exercise, unfamiliar humid environments, and minor psychosocial stressors, each of which is known to influence respiratory drive, chemosensitivity, sympathetic arousal, airway resistance, and perceived breathing effort. Clinical examination, oxygen saturation monitoring, blood studies, electrocardiogram, and chest radiography were unremarkable. Mental status examination showed intact affect regulation in the absence of anxiety. Symptom resolution during sleep supports a cortically mediated disturbance in volitional respiratory modulation. Management consisted of breathing retraining, relaxation exercises, autonomic regulation strategies, strict stimulant avoidance, and intermittent low-dose benzodiazepines during acute episodes, leading to a significant diminution in symptom frequency. This case emphasizes the importance of recognizing functional breathing disturbances in the absence of psychiatric comorbidity. It highlights the need for an integrated biopsychophysiological model guiding diagnosis and intervention in unexplained dyspnea.